The invention firstly relates to a weaving machine for weaving pile fabrics consisting of weft yarns, backing warp yarns and pile warp yarns comprising:                one or several spacers extending between the pile warp yarns and which are provided either to realize a constant pile height between two pile fabrics formed, or to determine the pile loop height in one or several pile fabrics comprising pile loops;        one or several holders for clamping the spacers;        one or several shed forming devices, driving heddles through which backing and/or pile warp yarns extend in order to position these warp yarns with respect to the weft yarns;        a yarn supply;a zone for supplying pile warp yarns extending between the yarn supply and the heddles controlled by the shed forming device, and one or several holders being installed between the yarn supply and the one or several shed forming devices in order to clamp the spacers.        
Secondly, the invention relates to a method for weaving such pile fabrics.
Thirdly, the invention relates to a spacer for such a weaving machine.
When weaving pile fabrics, most of the time, lancets are used as spacers. These spacers are used for the following functions:                to keep the fabrics formed at a distance in order to realize a uniform pile height. For a long period already, this technique is used for weaving face-to-face on face-to-face weaving machines with one single lancet for each reed dent or for each warp system;        to determine the loop height in a loop fabric. With this technique the backing fabric is formed on the one side (upper or lower side) of the spacer, and a pile yarn is laid around an additional weft, forming a loop, which most of the time is provided to be removed from the fabric later on, when this part of the fabric has left the spacer. Such a weft yarn is called a lost pile loop weft yarn. This technique is used both for single fabrics, when only one fabric with pile loops is produced and for face-to-face weaving, where one or two sets of spacers are used and two fabrics with pile loops are produced at the same time.        
In EP 1 347 087 a device and a method are described to weave two fabrics with pile loops at a time on a face-to-face weaving machine by using upper and lower spacers (lancets), a weft insertion device being provided in order to insert weft yarns between the upper and lower spacer. These spacers are comprising at least two parts, the first parts of which are extending between the upper and the lower ruler. These parts are situated at a short distance from one another and each of them is serving to determine the loop height of the pile loops of the upper and the lower fabric respectively. Furthermore, these spacers have second parts situated at a greater distance from one another. To that effect, the spacers have been buckled between the first and second parts. In this manner it has been made possible that one of the weft insertion means will be able to move between the spacers in order to insert a weft yarn. The spacers have a back part taken up in the holder. In one of the preferred embodiments of the invention described in EP 1 347 087 this spacer is represented as used in practice, i.e. a compact holder clamping the back parts of both the upper and the lower spacer, this holder being connected to the frame of the machine.
Also with face-to-face weaving techniques using one single set of spacers for weaving fabrics with a cut pile and with weaving techniques for single fabrics for weaving pile loop fabrics, the extremities of the spacers of the single set of spacers at the far side of the weaver, are taken up by a similar holder.
When weaving pile fabrics, the warp yarns are supplied from the rear of the weaving machine and they are brought into the right position by the shed forming elements in order to realize the shed necessary to obtain the pattern desired for the backing and pile fabrics. In the shed, the backing warp yarns (binding and tension warp yarns) to form the backing fabric for the upper and lower fabrics are brought into their requested position in accordance with the weave structure desired by means of heddle frames moving up and down, comprising a set of heddles which are distributed right across the width of the weaving machine. Each heddle being provided with a heddle eye, through which a backing warp yarn is conducted. The backing warp yarns are supplied from one or several backing warp beams through separating bars distributing the backing warp yarns between the upper and the lower fabric. The backing warp yarns, which are destined for the upper fabric, are conducted above the holder of the spacers to further extend through heddle eyes. The backing warp yarns for the lower fabric are conducted below the holder of the spacers before they extend through the heddle eyes.
This manner to supply the yarn will enable the backing warp yarns to obtain the position required to realize the shed which is required for the backing weave selected, without the backing warp yarns getting in touch with the holder of the spacers.
The angle formed between the direction in which the backing warp yarn is moving before and after its passage through the heddle eye may be thus kept limited, so that the force component of the stretching force in the yarn, more particularly the component to be surmounted by the weaving frame in order to move up and down the backing warp yarn will remain limited. Thus the load on the weaving frame will be restricted and operating and positioning the weaving frame will be simplified.
Pile warp yarns may be supplied from a pile warp beam in case the same amount of all the pile warp yarns situated next to one another will be used, but more often they are supplied from a weaving creel in which a bobbin spindle is provided for each pile warp yarn on which a bobbin containing the pile warp yarn having the required properties (e.g. the color) is provided. From the bobbin, the yarn is conducted through a separating grid which is situated between the weaving creel and the weaving machine and further via spindles separating the pile warp yarns in order to split up the pile warp yarns in layers per color, so that for each layer one yarn per warp system and usually also, for each layer, one yarn for each reed tooth is supplied to form the fabric in the weaving machine. The pile warp yarns being conducted through heddle eyes of heddles of either a weaving frame or a harness arrangement of a Jacquard machine. The shed forming device is controlling the movement of the heddles and therefore the position of the pile warp yarns, on the basis of data relating to the pattern to be obtained. The pile warp yarns are tensioned in the weaving creel, for instance, by applying a weight element to strain the yarn.
In weaving machine where lancets are used as spacers, because of the presence of a lancet holder on the center line of the shed, the pile warp yarns are divided into a part of the pile warp yarns being conducted through the separating spindles for the pile warp yarns which are situated above the lancet holder (for instance, for the pile warp yarns that are woven in as dead piles in the upper fabric) and into a part of the pile warp yarns being conducted through the separating spindles of the pile warp yarns situated below the lancet holder (for instance for the pile warp yarns being woven in as dead piles in the lower fabric). Separating these separating spindles for the pile warp yarns into two parts also requires an independent adjustability of the two sets of separating spindles for the pile warp yarns. Thus preventing the holders for the separating spindles for the pile warp yarns to be provided with partitions to strengthen them. Without these partitions the separating spindles for the pile warp yarns must have a considerably larger diameter in order to reduce the deflection of the separating spindles for the pile warp yarns. This larger diameter in combination with the larger number of pile warp yarns, will cause not only a layer of pile warp yarns to be running over its own separating spindle, but also that it will get in touch with another separating spindle. Because of this, the tension of the yarn will be increased, but most of all will cause problems and the risk of yarn breaks.
Because, contrary to the backing warp yarns, the pile warp yarns may be tied up around weft yarns in both the upper fabric and the lower fabric, the yarn selection positions may be further apart when the shed is formed. In case the weaving machine is equipped with lancets, it becomes difficult, if not impossible, to supply the pile warp yarns when the fabric is formed, not in a single selection position to form the shed of these pile warp yarns, these yarns may come in contact with the lancet holder. Such a contact may conduce to a greater tension to be built up and to an increased wear of the pile warp yarns. Causing an increase of the risk of yarn breakage, which may cause machine downtime and fabrics of an inferior quality. The consequences of such contacts will be an increase of the load the pile warp yarn is exerting on the heddle, because the force component in the direction of motion of the heddle will be increased. This means an increase of the load on the shed forming device and may cause an inaccurate or incorrect formation of the shed and an increased energy consumption.
A further disadvantage consists in the fact that a motion from a position in which there is a contact with the lancet holder to a position without any contact with the lancet holder, causing the yarn to be returned to the weaving creel, this returning of yarn will be greater when the pile warp yarn is in touch with the lancet holder, than when the pile warp yarn is not in touch with the lancet holder. This has a particularly harmful influence on the return springs of the harness. When returning the yarns during a downward motion, the return spring, as an element controlled in a negative sense, will be unable to follow rapidly enough to absorb this greater return of yarns to the weaving creel. This will conduce to pile warp yarns being no longer tensioned for a short period, which has an adverse effect on the weaving process. Finally, this may cause pile warp yarns and harness cords to get entangled, which finally may cause machine downtime, so that important manual interventions may be required. The resulting shock load on the return springs will cause in turn a shorter life of these return springs. These problems will become the greater as the operating speeds will be increased, the shed required to operate the machine is increasing and the number of pile warp yarns will be increased (more colors or higher densities).
In order to avoid contact between pile warp yarns and the lancet holder, it is best to bring the separating spindles for the pile warp yarns as close as possible to the fell of the fabric. However, it is a matter of course that these guiding spindles should be arranged after the heddle devices controlled by the shed forming devices for backing and pile warp yarns. However, the closer to the fell of the fabric the separating spindles for the pile warp yarns, the greater the force component of the strain in the pile warp yarn will become, the shed forming device in one of its selection positions of the shed has to overcome to bring the pile warp yarns from that position into a position required. In order to keep this force component as restricted as possible, the separating spindles for the pile warp yarns should be installed as much to the rear of the weaving machine as possible. Indeed, bringing the separating spindles for the pile warp yarns as more to the rear of the weaving machine, will lead to a contact between the pile warp yarns and the lancet holder in certain positions.
Furthermore, when weaving fabrics with a long pile where pile heights of more than 70 mm, more than 100 mm and up to over 200 mm long are realized, so-called spoon lancets are used (see publication of the Belgian patent BE 1005394 and the publication of the European patent EP 536551). These lancets have a profiled length, the height of the top part being greater than the height of the central part of the rapiers.
Up to the present, these so-called spoon lancets are taken up in one central lancet holder, having the disadvantage that these lancets, because of their weight at the top, are sagging and are difficult to install. The suspension thus obtained is rather unstable.
The purpose of the present invention is to find a solution for the above-mentioned problem, where, in a compact design, the pile warp yarns may be supplied to the zone where the shed is formed by shed forming devices, such that the load on the heddles controlled by the shed forming devices, exerted by the pile warp yarns will be kept within certain limits, and where the pile warp yarns will not come in touch, or to a lesser extent, with the holder of the spacers, and where a stable suspension and positioning of the spacers in the weaving machine will be obtained.